freebsd-dev/sys/i386/include/pcpu.h
John Baldwin 6caa8a1501 Overhaul of the SMP code. Several portions of the SMP kernel support have
been made machine independent and various other adjustments have been made
to support Alpha SMP.

- It splits the per-process portions of hardclock() and statclock() off
  into hardclock_process() and statclock_process() respectively.  hardclock()
  and statclock() call the *_process() functions for the current process so
  that UP systems will run as before.  For SMP systems, it is simply necessary
  to ensure that all other processors execute the *_process() functions when the
  main clock functions are triggered on one CPU by an interrupt.  For the alpha
  4100, clock interrupts are delievered in a staggered broadcast fashion, so
  we simply call hardclock/statclock on the boot CPU and call the *_process()
  functions on the secondaries.  For x86, we call statclock and hardclock as
  usual and then call forward_hardclock/statclock in the MD code to send an IPI
  to cause the AP's to execute forwared_hardclock/statclock which then call the
  *_process() functions.
- forward_signal() and forward_roundrobin() have been reworked to be MI and to
  involve less hackery.  Now the cpu doing the forward sets any flags, etc. and
  sends a very simple IPI_AST to the other cpu(s).  AST IPIs now just basically
  return so that they can execute ast() and don't bother with setting the
  astpending or needresched flags themselves.  This also removes the loop in
  forward_signal() as sched_lock closes the race condition that the loop worked
  around.
- need_resched(), resched_wanted() and clear_resched() have been changed to take
  a process to act on rather than assuming curproc so that they can be used to
  implement forward_roundrobin() as described above.
- Various other SMP variables have been moved to a MI subr_smp.c and a new
  header sys/smp.h declares MI SMP variables and API's.   The IPI API's from
  machine/ipl.h have moved to machine/smp.h which is included by sys/smp.h.
- The globaldata_register() and globaldata_find() functions as well as the
  SLIST of globaldata structures has become MI and moved into subr_smp.c.
  Also, the globaldata list is only available if SMP support is compiled in.

Reviewed by:	jake, peter
Looked over by:	eivind
2001-04-27 19:28:25 +00:00

98 lines
3.2 KiB
C

/*-
* Copyright (c) Peter Wemm <peter@netplex.com.au>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _MACHINE_GLOBALDATA_H_
#define _MACHINE_GLOBALDATA_H_
#include <machine/segments.h>
#include <machine/tss.h>
/* XXX */
#ifdef KTR_PERCPU
#include <sys/ktr.h>
#endif
/*
* This structure maps out the global data that needs to be kept on a
* per-cpu basis. genassym uses this to generate offsets for the assembler
* code, which also provides external symbols so that C can get at them as
* though they were really globals.
*
* The SMP parts are setup in pmap.c and locore.s for the BSP, and
* mp_machdep.c sets up the data for the AP's to "see" when they awake.
* The reason for doing it via a struct is so that an array of pointers
* to each CPU's data can be set up for things like "check curproc on all
* other processors"
*/
struct globaldata {
struct globaldata *gd_prvspace; /* self-reference */
struct proc *gd_curproc;
struct proc *gd_npxproc;
struct pcb *gd_curpcb;
struct proc *gd_idleproc;
struct timeval gd_switchtime;
struct i386tss gd_common_tss;
int gd_switchticks;
struct segment_descriptor gd_common_tssd;
struct segment_descriptor *gd_tss_gdt;
int gd_currentldt;
u_int gd_cpuid;
u_int gd_other_cpus;
SLIST_ENTRY(globaldata) gd_allcpu;
struct lock_list_entry *gd_spinlocks;
#ifdef KTR_PERCPU
#ifdef KTR
volatile int gd_ktr_idx;
char *gd_ktr_buf;
char gd_ktr_buf_data[KTR_SIZE];
#endif
#endif
};
#ifdef SMP
/*
* This is the upper (0xff800000) address space layout that is per-cpu.
* It is setup in locore.s and pmap.c for the BSP and in mp_machdep.c for
* each AP. genassym helps export this to the assembler code.
*/
struct privatespace {
/* page 0 - data page */
struct globaldata globaldata;
char __filler0[PAGE_SIZE - sizeof(struct globaldata)];
/* page 1 - idle stack (UPAGES pages) */
char idlestack[UPAGES * PAGE_SIZE];
/* page 1+UPAGES... */
};
extern struct privatespace SMP_prvspace[];
#endif
#endif /* ! _MACHINE_GLOBALDATA_H_ */